Prevents double-clicks on a tab close button from aslo maximizing the browser

ash/wm/toplevel_window_event_handler.cc

Index: ash/wm/toplevel_window_event_handler.cc
diff --git a/ash/wm/toplevel_window_event_handler.cc b/ash/wm/toplevel_window_event_handler.cc
index 8b6c9ba04542badc4444a7dc5fdb951afd4540a4..f20a13fc7dd2b90e8601a284defbc3a6d5236783 100644
--- a/ash/wm/toplevel_window_event_handler.cc
+++ b/ash/wm/toplevel_window_event_handler.cc
@@ -476,7 +476,10 @@ void ToplevelWindowEventHandler::HandleMousePressed(
         ConvertPointToParent(target, event->location()));
     AttemptToStartDrag(target, location_in_parent, component,
                        aura::client::WINDOW_MOVE_SOURCE_MOUSE);
-    event->StopPropagation();
+    // Set as handled so that other event handlers do no act upon the event
+    // but still receive it so that they receive both parts of each pressed/
+    // released pair.
+    event->SetHandled();
   } else {
     CompleteDrag(DRAG_COMPLETE);
   }
@@ -491,12 +494,13 @@ void ToplevelWindowEventHandler::HandleMouseReleased(
   CompleteDrag(event->type() == ui::ET_MOUSE_RELEASED ?
                    DRAG_COMPLETE : DRAG_REVERT);
   // Completing the drag may result in hiding the window. If this happens
-  // return true so no other handlers/observers see the event. Otherwise
-  // they see the event on a hidden window.
+  // mark the event as handled so no other handlers/observers act upon the
+  // event. They should see the event on a hidden window, to determine targets
+  // of destructive actions such as hiding. They should not act upon them.
   if (window_resizer_ &&
       event->type() == ui::ET_MOUSE_CAPTURE_CHANGED &&
       !target->IsVisible()) {
-    event->StopPropagation();
+    event->SetHandled();
   }
 }